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Metal ion

Marianne H Gillam, Nicole L Pratt, Maria C S Inacio, Elizabeth E Roughead, Sepehr Shakib, Stephen J Nicholls, Stephen E Graves
Background and purpose - It is unclear whether metal particles and ions produced by mechanical wear and corrosion of hip prostheses with metal-on-metal (MoM) bearings have systemic adverse effects on health. We compared the risk of heart failure in patients with conventional MoM total hip arthroplasty (THA) and in those with metal-on-polyethylene (MoP) THA. Patients and methods - We conducted a retrospective cohort study using data from the Australian Government Department of Veterans' Affairs health claims database on patients who received conventional THA for osteoarthritis between 2004 and 2012...
October 19, 2016: Acta Orthopaedica
Geon-Hyoung An, Do-Young Lee, Yu-Jin Lee, Hyo-Jin Ahn
The use of metal oxides as anode materials in Li-ion batteries (LIBs) are of significant interest to many potential technologies, due to their high theoretical capacity, cost-effectiveness, and environmentally friendly features. In spite of these considerable benefits, and ongoing progress in the field, important challenges exist, associated with structural degradation due to volume expansion of electrode materials. This leads to rapid capacity fading, and must be resolved in order to move towards the practical use of high-performance LIBs with ultrafast cycling stability...
October 19, 2016: ACS Applied Materials & Interfaces
S S Garcia, Q Du, H Wu
The oral cavity is a dynamic environment characterized by hundreds of bacterial species, saliva, and an influx of nutrients and metal ions such as copper. Although there is a physiologic level of copper in the saliva, the oral cavity is often challenged with an influx of copper ions. At high concentrations copper is toxic and must therefore be strictly regulated by pathogens for them to persist and cause disease. The cariogenic pathogen Streptococcus mutans manages excess copper using the copYAZ operon that encodes a negative DNA-binding repressor (CopY), the P1-ATPase copper exporter (CopA), and the copper chaperone (CopZ)...
December 21, 2015: Molecular Oral Microbiology
Anees A Ansari, Abdul K Parchur, Brijesh Kumar, S B Rai
The design of nanostructured materials with highly stable water-dispersion and luminescence efficiency is an important concern in nanotechnology and nanomedicine. In this paper, we described the synthesis and distinct surface modification on the morphological structure and optical (optical absorption, band gap energy, excitation, emission, decay time, etc.) properties of highly crystalline water-dispersible CaF2:Ce/Tb nanocrystals (core-nanocrystals). The epitaxial growth of inert CaF2 and silica shell, respectively, on their surface forming as CaF2:Ce/Tb@CaF2 (core/shell) and CaF2:Ce/Tb@CaF2@SiO2 (core/shell/SiO2) nanoarchitecture...
December 2016: Journal of Materials Science. Materials in Medicine
Chi He, Gaoshan Men, Bitao Xu, Jin Cui, Jinglian Zhao
The adsorption process and mechanism of dibenzothiophene (DBT) over metal-loaded phenolic resin-derived activated carbon (PR-AC) were firstly reported in this work. The metal component (Zn, Ni, or Cu) was respectively introduced to PR-AC support via an impregnation method. The effects of adsorbent component, initial DBT concentration, liquid hourly space velocity (LHSV), adsorption time, and adsorption temperature on the adsorption capacity of the adsorbents were systematically investigated. Furthermore, the adsorption mechanism was discussed by analyzing the properties of adsorption product and saturated adsorbent as well as adsorption kinetics...
October 18, 2016: Environmental Science and Pollution Research International
Jangsun Hwang, Mintai P Hwang, Moonhyun Choi, Youngmin Seo, Yeonho Jo, Jaewoo Son, Jinkee Hong, Jonghoon Choi
Heavy metal pollution has been a problem since the advent of modern transportation, which despite efforts to curb emissions, continues to play a critical role in environmental pollution. Copper ions (Cu(2+)), in particular, are one of the more prevalent metals that have widespread detrimental ramifications. From this perspective, a simple and inexpensive method of detecting Cu(2+) at the micromolar level would be highly desirable. In this study, we use porous silicon nanoparticles (NPs), obtained via anodic etching of Si wafers, as a basis for undecylenic acid (UDA)- or acrylic acid (AA)-mediated hydrosilylation...
October 18, 2016: Scientific Reports
Kaitlin A Doucette, Kelly N Hassell, Debbie C Crans
Improving efficacy and lowering resistance to metal-based drugs can be addressed by consideration of the coordination complex speciation and key reactions important to vanadium antidiabetic drugs or platinum anticancer drugs under biological conditions. The methods of analyses vary depending on the specific metal ion chemistry. The vanadium compounds interconvert readily, whereas the reactions of the platinum compounds are much slower and thus much easier to study. However, the vanadium species are readily differentiated due to vanadium complexes differing in color...
October 3, 2016: Journal of Inorganic Biochemistry
Mikko Laitaoja, Sari Isoniemi, Jarkko Valjakka, Istvan M Mándity, Janne Jänis
Small zinc finger (ZnF) motifs are promising molecular scaffolds for protein design owing to their structural robustness and versatility. Moreover, their characterization provides important insights into protein folding in general. ZnF motifs usually possess an exceptional specificity and high affinity towards Zn(II) ion to drive folding. While the Zn(II) ion is canonically coordinated by two cysteine and two histidine residues, many other coordination spheres also exist in small ZnFs, all having four amino acid ligands...
October 17, 2016: Protein Science: a Publication of the Protein Society
Jessica J Gruskos, Guangqian Zhang, Daniela Buccella
The study of intracellular metal ion compartmentalization and trafficking involved in cellular processes demands sensors with controllable localization for the measurement of organelle-specific levels of cations with sub-cellular resolution. We introduce herein a new two-step strategy for in situ anchoring and activation of a fluorescent Mg(2+) sensor within an organelle of choice, using a fast fluorogenic reaction between a tetrazine-functionalized pro-sensor, Mag-S-Tz, and a strained bicyclononyne conjugated to a genetically encoded HaloTag fusion protein of known cellular localization...
October 17, 2016: Journal of the American Chemical Society
Hui Cao, Siqi Zhu, Chao Yang, Ruiqi Bao, Liuniu Tong, Linrui Hou, Xiaogang Zhang, Changzhou Yuan
Mesoporous hetero-structures have drawn tremendous attention due to their unprecedented inherent advantages in advanced Li-ion batteries (LIBs). In this study, we developed a facile metal-organic-framework-engaged synthetic methodology for large-scale fabrication of two-dimensional (2D) mesoporous hetero-ZnFe2O4/ZnO nanosheets (ZFOZ NSs) with homogeneously dispersed hetero-nanodomains of spinel ZnFe2O4 and ZnO. When evaluated as a promising anode for LIB applications, the resultant 2D ultrathin mesoporous hetero-ZFOZ NSs exhibited extraordinary electrochemical Li storage performance with long-cycle behavior and large reversible capacities for next-generation LIB applications, thanks to the attractive synergetic contributions from ultrathin mesoporous architecture and electroactive bi-component hetero-interfaces at the nanoscale...
October 17, 2016: Nanotechnology
Tony Pham, Katherine A Forrest, KaiJie Chen, Amrit Kumar, Michael J Zaworotko, Brian Space
Molecular simulations of CO2 and H2 sorption were performed in MPM-1-Cl and MPM-1-TIFSIX, two robust molecular porous materials (MPMs) with the empirical formula [Cu2(adenine)4Cl2]Cl2 and [Cu2(adenine)4(TiF6)2], respectively. Recent experimental studies have shown that MPM-1-TIFSIX displayed higher CO2 uptake and isosteric heat of adsorption (Qst) than MPM-1-Cl [Nugent, P. S.; et al. J. Am. Chem. Soc. 2013, 135, 10950-10953.]. This was verified through the simulations executed herein, as the presented simulated CO2 sorption isotherms and Qst values are in very good agreement with the corresponding experimental data for both MPMs...
October 17, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Craig Waitt, Nashali M Ferrara, Henk Eshuis
The performance of the random phase approximation (RPA) is tested for ther- mochemistry and geometries of transition metal chemistry using various benchmarks obtained either computationally or experimentally. Comparison is made to popular (semi-)local, meta- and hybrid density functionals as well as to second-order Møller- Plesset perturbation theory (MP2) and its spin-component-scaled derivatives. The benchmarks sets include reaction energies, barrier heights and dissociation energies of prototype bond-activation reactions, dissociation energies for a set of large transition metal complexes, bond lengths and dissociation energies of metal hydride ions, and bond lengths and angles of a set of closed-shell first-row transition metal complexes...
October 17, 2016: Journal of Chemical Theory and Computation
Shibing Chu, Emanuele Coccia, Matteo Barborini, Leonardo Guidoni
Electron correlation plays a crucial role in the energetics of reactions catalyzed by transition metal complexes, such as water splitting. In the present work we exploit the performance of various methods to describe the thermodynamics of a simple but representative model of water splitting reaction, based on a single cobalt ion as catalyst. Density Functional Theory (DFT) calculations show a significant dependance on the the adopted functional and not negligible differences with respect to CSSD(T) findings are found along the reaction cycle...
October 17, 2016: Journal of Chemical Theory and Computation
Qin Wang, Katherine J Franz
Metal ions are essential for a wide range of physiological processes, but they can also be toxic if not appropriately regulated by a complex network of metal trafficking proteins. Intervention in cellular metal distribution with small-molecule or peptide chelating agents has promising therapeutic potential to harness metals to fight disease. Molecular outcomes associated with forming metal-chelate interactions in situ include altering the concentration and subcellular metal distribution, inhibiting metalloenzymes, enhancing the reactivity of a metal species to elicit a favorable biological response, or passivating the reactivity of a metal species to prevent deleterious reactivity...
October 17, 2016: Accounts of Chemical Research
Fan Wang, Shuyan Song, Kai Li, Junqi Li, Jing Pan, Shuang Yao, Xin Ge, Jing Feng, Xiao Wang, Hongjie Zhang
A green and cost-effective method, named the "solid dual-ions-transformation reaction", is reported to achieve the goal of successfully doping S and N into hollow carbon nanotubes. No harmful raw material is needed during the whole synthesis. Importantly, in the catalytic test of chemical reduction of p-nitrophenol by NaBH4 , the as-obtained S,N co-doped hollow carbon nanotubes exhibit ultrahigh catalytic performances.
October 17, 2016: Advanced Materials
Gongyu Li, Siming Yuan, Yang Pan, Yangzhong Liu, Guangming Huang
The identification of endogenous proteins as well as their binding to metal ions in living cells is determined by combining pulsed electrophoretic separations with nanoelectrospray ionization followed by mass spectrometric detection. This approach avoids problems resulting from the complicated cellular environment. In this manner we demonstrate the rapid identification (300 ms or less) of intact proteins from living E. coli cells including the complexation of calmodulin with calcium ion. The latter showed different binding states from those observed in in-vitro studies...
October 17, 2016: Analytical Chemistry
Kevin J Sheridan, Beatrix Elisabeth Lechner, Grainne O' Keeffe, Markus A Keller, Ernst R Werner, Herbert Lindner, Gary W Jones, Hubertus Haas, Sean Doyle
Ergothioneine (EGT; 2-mercaptohistidine trimethylbetaine) is a trimethylated and sulphurised histidine derivative which exhibits antioxidant properties. Here we report that deletion of Aspergillus fumigatus egtA (AFUA_2G15650), which encodes a trimodular enzyme, abrogated EGT biosynthesis in this opportunistic pathogen. EGT biosynthetic deficiency in A. fumigatus significantly reduced resistance to elevated H2O2 and menadione, respectively, impaired gliotoxin production and resulted in attenuated conidiation...
October 17, 2016: Scientific Reports
Canan Turgut, Godhuli Sinha, Jouko Lahtinen, Kai Nordlund, Mohammed Belmahi, Patrick Philipp
Quantitative analyses in secondary ion mass spectrometry (SIMS) become possible only if ionization processes are controlled. The Storing Matter technique has been developed to circumvent this so-called matrix effect, primarily for inorganic samples, but has also been extended to organic samples. For the latter, it has been applied to polystyrene in order to investigate the extent of damage in the polymer, its fragmentation during the sputter deposition process and the effect of the deposition process on the spectra taken by Time-of-Flight SIMS (ToF-SIMS)...
October 2016: Journal of Mass Spectrometry: JMS
Mengzhe Guo, Dengyang Yin, Jie Han, Cheng Guo, Xiao Li, Liyan Zhang, Yan Du, Haibo Wang, Daoquan Tang
RATIONALE: Mass spectrometry has been developed as one of the common tools for the analysis of the organometallic systems in the gas phase over decades. The study of the fragmentation of organics-metal complexes has attracted much attention since the interesting dissociation pathways exhibited by these compounds are usually different from the protonated analogues. METHODS: In this work, iohexol complexed with different dications such as Mg(2+) , Cu(2+) , and Zn(2+) have been investigated by ESI tandem mass spectrometry...
October 17, 2016: Rapid Communications in Mass Spectrometry: RCM
Tifeng Xia, Tao Song, Gege Zhang, Yuanjing Cui, Yu Yang, Zhiyu Wang, Guodong Qian
A series of isomorphic lanthanide metal-organic frameworks Ln(TATAB)(DMF)4(H2O)(MeOH)0.5 (LnTATAB, Ln = Eu, Tb, Sm, Dy, Gd, H3TATAB = 4,4',4''-s-triazine-1,3,5-triyltri-p-aminobenzoic acid) have been solvothermally synthesized and structure characterized. Among these MOFs, TbTATAB exhibits good water-stability and high quantum yield. Because mercury ions have a high affinity to nitrogen atoms, and the space between multi-nitrogen atoms from triazine and imino is suitable for interacting with Hg2+ ions, TbTATAB shows highly selective and sensitive detection of Hg2+ in aqueous solution with the detection limit of 4...
October 16, 2016: Chemistry: a European Journal
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